By switching to dark mode you can reduce the energy consumption of our digital service.

Pumping behaviour of solar irrigation farmers for assessing the sustainability of groundwater in Bangladesh and India

This study aims to evaluate the impact of SIPs on pumping behaviour of farmers and its subsequent effect on overall groundwater resources in Bangladesh and India.
Multiple Authors

This weADAPT article is an abridged version of the original text, which can be downloaded from the right-hand column. We highlight some of the brief’s key messages below, but please access the original text for more comprehensive detail, full references, or to quote text. 

Summary

The increasing use of Solar Irrigation Pumps (SIPs) has raised concerns about the overexploitation of groundwater. This study aims to evaluate the impact of SIPs on pumping behaviour of farmers and its subsequent effect on overall groundwater resources in Bangladesh and India.

In Bangladesh, the study is being carried out in the intensively irrigated North-West region, where the government is promoting the fee- for-service model for solar irrigation. This model creates a solar irrigation command area by setting up centralized sponsored SIPs. In India, the study is being conducted in the state of Gujarat, where the grid-connected solar irrigation pump model has been implemented under the Suryashakti Kisan Yojana (SKY) scheme.

Introduction

Groundwater pumping has encouraged unsustainable abstraction rates in regions of Bangladesh and India. Consequently, the anticipated rise in SIPs leads to concerns of groundwater overexploitation. This, in turn leads to decreasing well yields and falling water tables. It is assumed that in the event of free electricity (solar) and no financial incentive to limit pumping, farmers will likely increase the volume of groundwater withdrawn. This may happen through overirrigation, expansion of the area under irrigation (for personal use or sale), or an increase in the area of high water-intensive crops.

However, changes in farmers’ irrigation behavior depend on a range of factors, such as the type of solar irrigation model used (on or off-grid solar irrigation pumps), existing crop patterns, developed value chain markets, and biophysical factors such as water availability (which depends on the climate, aquifer type and groundwater tables). Therefore, understanding how farmers’ pumping behaviour changes with the introduction of solar irrigation is critical to determining the expected impact on groundwater sustainability.

This study evaluates the impact of SIPs on farmers’ groundwater abstraction practices in Bangladesh and India as part of the Solar Irrigation for Agricultural Resilience in South Asia (SoLAR-SA) project.

Solar irrigation and groundwater in Bangladesh

In Bangladesh, the Infrastructure Development Company Limited (IDCOL) has taken the initiative to implement the fee-for-service model for solar irrigation. This model involves centralized sponsored SIPs with power ranging from 5 kW to 20 kW. However, there is concern that the relatively lower cost and ease of using SIPs, compared to diesel pumps, may increase groundwater abstraction. Currently, around 1.6 million pumps are used for groundwater irrigation in Bangladesh, with 80% being diesel pumps that irrigate approximately 80% of the total irrigated area.

Against this backdrop, this study aims to evaluate the impact of SIPs on farmers’ irrigation behavior and the subsequent effects on overall groundwater levels and resources. The study is being carried out in the most groundwater-stressed region of Bangladesh, namely the northwest (Rangpur and Rajshahi divisions) (as shown in Figure 2). In the dry season, boro paddy is the region’s dominant and main water-consuming crop, primarily fed by groundwater.

Schematic of a centralized SIP (top) versus a schematic of a grid-connected SIP (bottom).
Source: Illustration by Aariz Raza, IWMI.

Solar irrigation and groundwater in India

The Indian government is actively promoting solar irrigation through policies and programs. The flagship Pradhan Mantri Kisan Urja Suraksha evam Utthaan Mahabhiyan (PM-KUSUM) scheme seeks to solarize 3.5 million irrigation pumps in total – 2 million through standalone solar pumps and 1.5 million by grid-connecting existing agriculture pumps.

Approximately 14 million electric pumps, mostly running on subsidized electricity, have played a vital role in the expansion of groundwater irrigation in India but have also led to uncontrolled groundwater overexploitation in many parts of the country. Groundwater in northwest and southern peninsular India, where most of these electric pumps are located, has seen widespread depletion. Continued unsustainable use of groundwater can reduce India’s cultivated area by up to 20% and up to 68% in groundwater-depleted regions.

This study evaluates the impact of grid- connected solar pumps on farmers’ pumping behavior and its subsequent effect on overall groundwater resources. The study is being conducted in the state of Gujarat, where the grid-connected SIP model has been implemented under the Suryashakti Kisan Yojana (SKY) scheme. More than 90 feeders have been solarized, with over 75% of farmers’ irrigation pumps now being powered by solar energy.

Measuring and comparing farmers’ groundwater abstraction

The study is taking a slightly different approach in India and Bangladesh to account for the different solar irrigation models. The common denominator is comparing the abstraction behavior of solar farmers with that of non- solar farmers.

In Bangladesh, the water application of diesel and solar farmers for boro paddy, the main post-monsoon irrigated crop, is being monitored for 100 farmer plots (each for solar and diesel farmers) in six SIPs and nearby villages. These SIPs and diesel farmers were selected after initial surveys, during which detailed data on crops, land, soil and pump characteristics were collected. The water application is being monitored by combining instrumentation (flow meters in SIPs) and regular flow tests with farmer irrigation logbooks. SIP operators and diesel farmers were trained before the monitoring began.

In India, the study uses an energy-based approach to monitor farmer groundwater use in India, utilizing state- of-the-art energy monitoring data from the SKY scheme. This approach relies on converting data on energy used for pumps (by farmers) to data on groundwater abstraction based on a set of defined relationships. The monitoring of approximately 160 farmers is being carried out, including comprehensive data collection on their pumps, crops, pump flow rates and energy use. This data is being used to derive current and past groundwater abstraction for a larger set of solar and non-solar farmers.

The analysis (currently under way) will involve comparing the groundwater abstraction behaviour of solar and non-solar farmers in India and Bangladesh. These results will be of great interest to policymakers, researchers and practitioners working in the field of sustainable agriculture and water management, as they will provide valuable insights into the potential of solar irrigation to address the groundwater depletion challenge in India and Bangladesh.

Suggested citation

Alam, M. F., Sikka, A., Pavelic, P., Krishan, S., Dodiya, M., Habib, A., & Haque, A. (2022). Pumping behavior of solar irrigation farmers for assessing the sustainability of groundwater in Bangladesh and India. International Water Management Institute. IWMI Issue Brief.

Add your project

Exchange your climate change adaptation projects and lessons learned with the global community.